多光束共振光压作用下钠原子束的偏转

本文报道了多光束共振光压作用下钠原子束偏转的实验研究结果。文中提出了用多光束与原子束相互作用以增大原子束的偏转量,并可大大降低对激光功率的要求。用一台染料激光器照射钠原子束得到1×10^-2rad的偏转角,偏转距离约7.2mm,并用激光诱导原子束荧光的方法检测原子束的偏转。     

The high resolution infrared spectrum of the 2ν2 + ν3 and ν1 + ν2 + ν3 bands of 14N16O2: Vibration and vibration-rotation constants of the electronic ground state of 14N16O2

The A-type bands, 2ν₂ + ν₃ and ν₁ + ν₂ + ν₃, with band centers at 3092 and 3638 cm^?1, respectively, of ¹⁴N¹⁶O₂ have been measured with resolution of 0.03 cm^?1 or better. Spectroscopic constants have been derived for the upper states of both bands. Infrared determined band constants have been combined with laser-excited resonance fluorescence data to obtain a set of vibration and vibration-rotation constants for the ground state of ¹⁴N¹⁶O₂.     

The high resolution infrared spectrum of the ν1 band of HOCl

The ν₁ bands of HO³⁵Cl and HO³⁷Cl have been recorded. Both the A- and B-type rotational transitions of these hybrid bands have been completely assigned, and spectroscopic constants have been obtained for both the ground and upper state. The ratio of the electric dipole moment derivatives $\text{(}\text{?μ}{}_{\mathrm{a}}\text{?Q}{}_1\text{)}\text{(}\text{?μ}{}_{\mathrm{b}}\text{?Q}{}_1$ has been found to be 0.985 ± 0.05 for ν₁.     

High-resolution infrared spectrum of the 859- and 1711-cm−1 bands of carbonyl sulfide (OCS)

The ν₁ and 2ν₁ bands of OCS have been measured using grating spectrometers and a tunable diode laser spectrometer. Preliminary wavenumbers for OCS absorption lines useful for calibrating tunable laser systems are given for the wavenumber intervals 825 to 885 cm^?1 and 1665 to 1737 cm^?1. Measurements and an analysis are given for the bands 10⁰0-00⁰0, 11¹0-01¹0, 20⁰0-00⁰0, 21¹0-01¹0, and 30⁰0-10⁰0 of the ¹⁶O¹²C³²S isotopic species and for the 20⁰0-00⁰0 band of the ¹⁶O¹³C³²S and ¹⁶O¹²C³⁴S species. Effective band constants are given for these bands.     

Electronic ground state of iron in octamethyltetrabenzporphyriniron(II), a new square planar ferrous porphyrin

Reaction of iron powder with 1,3,4,7-tetramethylisoindole at 350° affords the square planar complex octamethyl-tetrabenzporphyriniron(II), whose magnetic moment indicates a spin quintet ground state. Mössbauer measurements at 4.2°K in an applied magnetic field of 50 kG show that the electric field gradient at iron is positive and axially symmetric, consistent with a ⁵B_2g ground term. The bistetrahydrofuran adduct is also high spin, whereas the bispyridine adduct is diamagnetic with ¹A_1g ground state. Comparisons are made with data for the related tetraphenylporphiniron(II) and phthalocyanineiron(II) derivatives.     

裂缝的张开位移和应变的关系

本文采用Kármán-钱处理亚音速流动方法的精神。处理了弹塑性断裂力学问题.通过建立的“双弹性”模型,从理论上得到了裂缝端部的张开位移和应变的方程组.实例计算结果表明,理论值全部落在实验结果的分散带内.文中并从理论上解释了实验结果与材料的性质及实验条件的关系.本文的结果不仅为宽板实验所证实,也被文献[2]的实验所证实.同时也表明。公式(37)用于工程,能够分析压力容器上应变裂缝的容许极限.     

Infrared spectrum of HCN and HCN

The high-resolution spectrum of H¹²C¹⁴N has been measured near 4870 and 6060 cm⁻¹. The following bands have been identified and analyzed: 01¹2-00⁰0, 02⁰2-01¹0, 02²2-01¹0, 04⁰1-00⁰0, 11¹1-00⁰0, 12⁰1-01¹0, and 12²1-01¹0. The C---N stretching fundamental (ν₃) of H¹²C¹⁵N has also been measured near 2100 cm⁻¹. This fundamental is found to be 3 cm⁻¹ higher than previously reported. Other bands that have been identified in the H¹²C¹⁶N spectrum are 03¹0-00⁰0, 04⁰0-01¹0, 04²0-01¹0, and 01¹1-01¹0.     

High-resolution infrared spectroscopy in the 1,200-1,300 cm(-1) region and accurate theoretical estimates for the structure and ring-puckering barrier of perfluorocyclobutane

We present experimental infrared spectra and theoretical electronic structure results for the geometry, anharmonic vibrational frequencies, and accurate estimates of the magnitude and the origin of the ring-puckering barrier in C4F8. High-resolution (0.0015 cm-1) spectra of the nu12 and nu13 parallel bands of perfluorocyclobutane (c-C4F8) were recorded for the first time by expanding a 10% c-C4F8 in helium mixture in a supersonic jet. Both bands are observed to be rotationally resolved in a jet with a rotational temperature of 15 K. The nu12 mode has b2 symmetry under D2d that correlates to a2u symmetry under D4h and consequently has +/- <-- +/- ring-puckering selection rules. A rigid rotor fit of the nu12 band yields the origin at 1292.56031(2) cm-1 with B' = 0.0354137(3) cm-1 and B' ' = 0.0354363(3) cm-1. The nu13 mode is of b2 symmetry under D2d that correlates to b2g under D4h, and in this case, the ring-puckering selection rules are +/- <-- -/+ . Rotational transitions from the ground and first excited torsional states will be separated by the torsional splitting in the ground and excited vibrational states, and indeed, we observe a splitting of each transition into strong and weak intensity components with a separation of approximately 0.0018 cm-1. The strong and weak sets of transitions were fit separately again using a rigid rotor model to give nu13(strong) = 1240.34858(4) cm-1, B' = 0.0354192(7) cm-1, and B' ' = 0.0354355(7) cm-1 and nu13(weak) = 1240.34674(5) cm-1, B' = 0.0354188(9) cm-1, and B' ' = 0.0354360(7) cm-1. High-level electronic structure calculations at the MP2 and CCSD(T) levels of theory with the family of correlation consistent basis sets of quadruple-zeta quality, developed by Dunning and co-workers, yield best estimates for the vibrationally averaged structural parameters r(C-C) = 1.568 A, r(C-F)alpha = 1.340 A, r(C-F)beta = 1.329 A, alpha(F-C-F) = 110.3 degrees , thetaz(C-C-C) = 89.1 degrees , and delta(C-C-C-C) = 14.6 degrees and rotational constants of A = B = 0.03543 cm-1 and C = 0.02898 cm-1, the latter within 0.00002 cm-1 from the experimentally determined values. Anharmonic vibrational frequencies computed using higher energy derivatives at the MP2 level of theory are all within <27 cm-1 (in most cases <5 cm-1) from the experimentally measured fundamentals. Our best estimate for the ring-puckering barrier at the CCSD(T)/CBS (complete basis set) limit is 132 cm-1. Analysis of the C4F8 electron density suggests that the puckering barrier arises principally from the sigmaCC-->sigmaCF hyperconjugative interactions that are more strongly stabilizing in the puckered than in the planar form. These interactions are, however, somewhat weaker in C4F8 than in C4H8, a fact that is consistent with the smaller barrier in the former (132 cm-1) with respect to the latter (498 cm-1).     

How the central torsion angle affects the rates of nonradiative decay in some geometrically restricted p-quaterphenyls

A small series of p-quaterphenyl derivatives has been prepared in which the dihedral angle (phi) for the two central rings is constrained by dialkoxy spacers of varying length. The photophysical properties of these compounds remain comparable, but there is a clear correlation between the rate constants for nonradiative decay of both singlet and triplet excited states and phi in fluid solution. The rates tend toward a minimum as phi approaches 90 degrees . These effects are attributed to the general phenomenon of extended delocalization and can be traced to a combination of changes in the Huang-Rhys factor and the electron-vibrational coupling matrix element, both relating to displacement of the relevant potential energy surfaces and to the medium-frequency vibronic mode coupled to decay. The latter effect arises because of different levels of conjugation in the ground-state molecule. Such findings might have important implications for the design of improved light-emitting diodes. A similar angle dependence is noted for the yield of the pi-radical cation formed on photoionization in a polar solvent, but here, the effect is due to variations in the respective energy gaps between the relevant excited states.     

低温等离子体转化NO/O2/N2气氛中NO的实验研究

通过建立低温等离子体实验系统, 研究了介质阻挡放电型低温等离子体反应器作用于NO/O2/N2混合气体系时, NO, O2初始浓度对NO的转化效率的影响以及NOx, O3浓度随能量密度的变化关系. 低温等离子体作用于NO/O2/N2混合气体系时, NO同时发生氧化还原反应, 氧化反应占主导地位, 大部分NO转化为NO2; NO转化率随O2, NO初始浓度增大而降低, 能量密度在450～600 J/L时转化率较高; 产生的O3浓度随能量密度的增大呈先增后减的趋势.